1. Field of the Invention
The present invention relates to a system for determining a road surface condition under a traveling vehicle, and particularly to a system for determining a road surface condition using vehicular information from a plurality of vehicles traveling along the same location within a predetermined space of time.
2. Description of the Related Art
In order to raise the travel safety of a vehicle, it is desired to accurately estimate the condition of the road surface on which the vehicle is traveling and to have the information fed back to vehicle control. If the road surface condition can be estimated, the safety of vehicular driving can be enhanced markedly since it becomes possible to turn on an advanced control of ABS braking, for instance, before the driver initiates a danger-avoiding control, such as braking or steering.
As methods having been proposed for estimating the condition of a road surface under a traveling vehicle, there are methods for estimating the condition of a road surface under a traveling vehicle by detecting the vibration of the tire of the traveling vehicle and estimating the road surface condition from the time-series waveform of the detected tire vibration (see Patent Documents 1 to 3, for instance) and methods for estimating a road surface condition from detected sound pressure levels of tire noise by detecting tire noise arising from a tire (see Patent Document 4, for instance).